The usual reduced visibility encountered underwater requires a source of light if a diver is to perform useful work. Because of the breathing equipment worn and protective clothing often required by a diver, his mobility and manual dexterity are severely reduced. These factors necessitate that the light source be rugged and simple to use. Finally, the electrical conductivity and pressure of the diver's water environment require exceptional watertight integrity to permit operation of a light source underwater. An underwater flashlight is capable of providing the necessary illumination under most circumstances provided that it is rugged and easy to carry, versatile in producing an appropriate beam pattern, and has secure watertight integrity including the switching arrangement. Since diving operations are often conducted at remote sites, far from sources of supply, it is desirable that a flashlight for divers be easy to repair and rechargeable from a generally available electrical power source.
Constructions for divers' flashlights have been provided using waterproof covers with control switches operated through seals. However, such seals wear and leak after a period of use. Parts removable from the flashlight, and openings in the flashlight such as battery charging connections must be sealed. The latter requirement poses problems servicing a diver's flashlight since the seals are often damaged or destroyed in use and are difficult to remake. Applicant's invention provides the operational features and characteristics desired in an underwater flashlight while at the same time eliminating or minimizing the noted hazards in providing a diver's flashlight capable of continued effective use and easy servicing.